With suitable thermal treatments, a nearly stoichiometric cordierite glass shows a variety of crystal morphologies on the external surfaces: lozenges, regular and elongated hexagons, spherical and square shaped particles. Iniitally, these morphologies were identified through optical and scanning electron microscopy techniques. Their structural features were distinguished by x-ray diffraction patterns, infrared and Raman microprobe spectra. It concludes that there are close structural similarities for:lozenges and glass matrix; regular and elongated hexagons; spherical and square particles. The lozenge crystals are known as X-phase. The hexagons belong to the u-cordierite metastable phase and the squares and spheres to the x-cordierite stable phase.
